Add random songs to MPD playlist

The first part puts currently playing song in a text-file for use in other programs. The second part adds random songs while there is less than 3 songs in the playlist. This probably isn't optimized or even good, to be frank, but it works. ^^

Update 1: As I have more than one mpd server running I figured it'd be more efficient catching the hostname as well as minimum tracks from stdin.
Update 2: Checks if we actually got a song to add as mpc add "" adds ALL the songs in your library.
Update 3: Cleaned up the code. Added NEXT_ON_ERROR to keep going if MPD stops while trying to play a song.
Update 4: Now backgrounds itself automagically. Also, functions are neat.
Update 5: Comments and exit 0.

#!/bin/bash

# stdin check
if (( "$#" < 2 )); then
  echo "Usage: `basename $0` HOSTNAME MIN_PLAYLIST_LENGTH [NEXT_ON_ERROR (y/N)]"
  exit 65
fi

# variables
host=$1
length=$2
state_file="$host.state"

export MPD_HOST=$host

if [ "$3" ]; then
  cont=${3^^}
  cont=${cont:0:1}
else
  cont="N"
fi

# go go go
echo "Mpd_Add v.0.6"
echo "Host: $host / Playlist length: $length"
echo "Next on error: $cont"

# loop
loop () {
 while true; do
  if `mpc version 2>/dev/null | grep -q 'mpd version:'`; then
    setState
        
    while (( `mpc playlist | grep -c ^` < $length )); do
      addSong
                  
      sleep 1
    done

    mpc idle &>/dev/null
  else
    sleep 30
  fi
 done
}

# output current status to file
# does conversion from utf8 to iso-8859-15 for compatability
#+with samurize on windows
setState() {
 if `mpc | grep -q '\[playing\]'`; then
  mpc --format "%artist% (%date%) %album% / %track% / %title%" current | iconv -s -c -f UTF-8 -t iso-8859-15 -o $state_file
 elif `mpc | grep -q '\[paused\]'`; then
  echo "pause" > $state_file

  if `mpc | grep -q 'single: on'`; then
    mpc -q single off && mpc -q stop && echo "not playing" > $state_file
  fi
 else
  if [ $cont = "Y" ]; then
    mpc -q play
  else
    echo "not playing" > $state_file
  fi
 fi
}

# add one random song from mpd library
addSong () {
 song=`mpc listall | sed -n $[RANDOM % $(mpc stats | grep Songs | awk '{print $2}')+1]p`

 if [ "$song" ]; then
  mpc -q add "$song"
 fi
}

# backgrounds the loop and exits main thread
loop &
exit 0